---
title: "Splunk protocol impersonation weak encryption selfsigned"
excerpt: "Digital Certificates
"
categories:
  - Application
last_modified_at: 2022-05-26
toc: true
toc_label: ""
tags:
  - Digital Certificates
  - Resource Development
  - Splunk Enterprise
  - Splunk Enterprise Security
  - Splunk Cloud
  - 
---



[Try in Splunk Security Cloud](https://www.splunk.com/en_us/products/cyber-security.html){: .btn .btn--success}

#### Description

On June 14th 2022, Splunk released vulnerability advisory addresing Python TLS validation which was not set before Splunk version 9. This search displays events showing WARNING of using Splunk issued default selfsigned certificates.

- **Type**: [Hunting](https://github.com/splunk/security_content/wiki/Detection-Analytic-Types)
- **Product**: Splunk Enterprise, Splunk Enterprise Security, Splunk Cloud

- **Last Updated**: 2022-05-26
- **Author**: Rod Soto, Splunk
- **ID**: c76c7a2e-df49-414a-bb36-dce2683770de


#### Annotations

<details>
  <summary>ATT&CK</summary>

<div markdown="1">


| ID             | Technique        |  Tactic             |
| -------------- | ---------------- |-------------------- |
| [T1588.004](https://attack.mitre.org/techniques/T1588/004/) | Digital Certificates | Resource Development |

</div>
</details>


<details>
  <summary>Kill Chain Phase</summary>

<div markdown="1">

* Exploitation


</div>
</details>


<details>
  <summary>NIST</summary>

<div markdown="1">

* DE.CM



</div>
</details>

<details>
  <summary>CIS20</summary>

<div markdown="1">

* CIS 3
* CIS 5
* CIS 16



</div>
</details>

<details>
  <summary>CVE</summary>

<div markdown="1">
| ID          | Summary | [CVSS](https://nvd.nist.gov/vuln-metrics/cvss) |
| ----------- | ----------- | -------------- |
| [](https://nvd.nist.gov/vuln/detail/) |  |  |



</div>
</details>

#### Search 

```
`splunkd` certificate event_message="X509 certificate* should not be used*" 
| stats count by host CN component log_level 
| `splunk_protocol_impersonation_weak_encryption_selfsigned_filter`
```

#### Macros
The SPL above uses the following Macros:
* [splunkd](https://github.com/splunk/security_content/blob/develop/macros/splunkd.yml)

> :information_source:
> **splunk_protocol_impersonation_weak_encryption_selfsigned_filter** is a empty macro by default. It allows the user to filter out any results (false positives) without editing the SPL.

#### Required field
* host
* CN
* event_message


#### How To Implement
Must upgrade to Splunk version 9 and Configure TLS in order to apply this search. Splunk SOAR customers can find a SOAR workbook that walks an analyst through the process of running these hunting searches in the references list of this detection. In order to use this workbook, a user will need to run a curl command to post the file to their SOAR instance such as "curl -u username:password https://soar.instance.name/rest/rest/workbook_template -d @splunk_psa_0622.json". A user should then create an empty container or case, attach the workbook, and begin working through the tasks.

#### Known False Positives
This searches finds self signed certificates issued by Splunk which are not recommended from Splunk version 9 forward.

#### Associated Analytic story
* [Splunk Vulnerabilities](/stories/splunk_vulnerabilities)




#### RBA

| Risk Score  | Impact      | Confidence   | Message      |
| ----------- | ----------- |--------------|--------------|
| 40.0 | 50 | 80 | Splunk default issued certificate at $host$ |


> :information_source:
> The Risk Score is calculated by the following formula: Risk Score = (Impact * Confidence/100). Initial Confidence and Impact is set by the analytic author. 

#### Reference

* [https://www.splunk.com/en_us/product-security](https://www.splunk.com/en_us/product-security)
* [https://docs.splunk.com/Documentation/Splunk/9.0.0/Security/EnableTLSCertHostnameValidation](https://docs.splunk.com/Documentation/Splunk/9.0.0/Security/EnableTLSCertHostnameValidation)
* [https://www.github.com/splunk/security_content/blob/develop/workbooks/splunk_psa_0622.json](https://www.github.com/splunk/security_content/blob/develop/workbooks/splunk_psa_0622.json)



#### Test Dataset
Replay any dataset to Splunk Enterprise by using our [replay.py](https://github.com/splunk/attack_data#using-replaypy) tool or the [UI](https://github.com/splunk/attack_data#using-ui).
Alternatively you can replay a dataset into a [Splunk Attack Range](https://github.com/splunk/attack_range#replay-dumps-into-attack-range-splunk-server)


* [https://raw.githubusercontent.com/splunk/attack_data/master/datasets/attack_techniques/T1558.004/splunk_protocol_impersonation_weak_encryption_selfsigned.txt](https://raw.githubusercontent.com/splunk/attack_data/master/datasets/attack_techniques/T1558.004/splunk_protocol_impersonation_weak_encryption_selfsigned.txt)



[*source*](https://github.com/splunk/security_content/tree/develop/detections/application/splunk_protocol_impersonation_weak_encryption_selfsigned.yml) \| *version*: **1**